Antheos is a go-lucky, vegetarian harpy that assists Master Chem, in the episode "Summer School" to capture Isabella in order to help his young spellbinder. She is not fond of traveling and is not use to Earth customs.
In the only episode where she is featured, Antheos simply adores animals like fish and mice.
For reasons unexplained, Antheos, an old friend of Master Chem owes him a favor. Because of the circumstances, he asks her to come to Rosemond to attack Isabella.